The Environmental Protection Agency (EPA) provides air pollution data about ozone and particulate matter (PM2.5) to CDC for the Tracking Network. The EPA maintains a database called the Air Quality System (AQS) which contains data from approximately 4,000 monitoring stations around the country, mainly in urban areas. Data from the AQS is considered the "gold standard" for determining outdoor air pollution. However, AQS data are limited because the monitoring stations are usually in urban areas or cities and because they only take air samples for some air pollutants every three days or during times of the year when air pollution is very high. CDC and EPA have worked together to develop a statistical model (Downscaler) to make modeled predictions available for environmental public health tracking purposes in areas of the country that do not have monitors and to fill in the time gaps when monitors may not be recording data. This data does not include "Percent of population in counties exceeding NAAQS (vs. population in counties that either meet the standard or do not monitor PM2.5)". Please visit the Tracking homepage for this information.View additional information for indicator definitions and documentation by selecting Content Area "Air Quality" and the respective indicator at the following website: http://ephtracking.cdc.gov/showIndicatorsData.action

The Office of Air and Radiation's (OAR) Ambient Air Quality Data (Current) contains ambient air pollution data collected by EPA, other federal agencies, as well as state, local, and tribal air pollution control agencies. Its component data sets have been collected over the years from approximately 10,000 monitoring sites, of which approximately 5,000 are currently active. OAR's Office of Air Quality Planning and Standards (OAQPS) and other internal and external users, rely on this data to assess air quality, assist in Attainment/Non-Attainment designations, evaluate State Implementation Plans for Non-Attainment Areas, perform modeling for permit review analysis, and other air quality management functions. Air quality information is also used to prepare reports for Congress as mandated by the Clean Air Act. This data covers air quality data collected after 1980, when the Clean Air Act requirements for monitoring were significantly modified. Air quality data from the Agency's early years (1970s) remains available (see OAR PRIMARY DATA ASSET: Ambient Air Quality Data -- Historical), but because of technical and definitional differences the two data assets are not directly comparable. The Clean Air Act of 1970 provided initial authority for monitoring air quality for Conventional Air Pollutants (CAPs) for which EPA has promulgated National Ambient Air Quality Standards (NAAQS). Requirements for monitoring visibility-related parameters were added in 1977. Requirements for monitoring acid deposition and Hazardous Air Pollutants (HAPs) were added in 1990. Most monitoring sites contain multiple instruments. Most also report meteorological data, including wind speed and direction, humidity, atmospheric pressure, inbound solar radiation, precipitation and other factors relevant to air quality analysis. The current system of sites represents a number of independently-defined monitoring networks with different regulatory or scientific purposes, such as the State and Local Air Monitoring System, the National Air Toxics Trends sites, the Urban Air Toxics sites, the IMPROVE visibility monitoring network, the air toxics monitoring sites for schools, and others. (A complete list of air quality monitoring networks is available at https://www.epa.gov/???). Efforts are under way through NCore Multipollutant Monitoring Network (https://www.epa.gov/ttnamti1/ncore/index.html) to streamline and integrate advanced air quality measurement systems to minimize costs of data collection. Measurements and estimates from these networks are collected across the entire U.S., including all states and territories, with emphasis on documenting pollutant exposures in populated areas.Sampling frequencies vary by pollutant (hourly, 3- and 8-hour, daily, monthly, seasonal, and annual measurements), as required by different NAAQS. Some 50,000 measurements per day are added to the EPA's central air quality data repository, the Air Quality System (AQS). All data, including meteorological information, is public and non-confidential and available through the AQS Data Mart (https://www.epa.gov/ttn/airs/aqsdatamart/). Generally, data for one calendar quarter are reported by the end of the following quarter; some values may be subsequently changed due to quality assurance activities.

This United States Environmental Protection Agency (US EPA) feature layer represents monitoring site data, updated hourly concentrations and Air Quality Index (AQI) values for the latest hour received from monitoring sites that report to AirNow.Map and forecast data are collected using federal reference or equivalent monitoring techniques or techniques approved by the state, local or tribal monitoring agencies. To maintain "real-time" maps, the data are displayed after the end of each hour. Although preliminary data quality assessments are performed, the data in AirNow are not fully verified and validated through the quality assurance procedures monitoring organizations used to officially submit and certify data on the EPA Air Quality System (AQS).This data sharing, and centralization creates a one-stop source for real-time and forecast air quality data. The benefits include quality control, national reporting consistency, access to automated mapping methods, and data distribution to the public and other data systems. The U.S. Environmental Protection Agency, National Oceanic and Atmospheric Administration, National Park Service, tribal, state, and local agencies developed the AirNow system to provide the public with easy access to national air quality information. State and local agencies report the Air Quality Index (AQI) for cities across the US and parts of Canada and Mexico. AirNow data are used only to report the AQI, not to formulate or support regulation, guidance or any other EPA decision or position.About the AQIThe Air Quality Index (AQI) is an index for reporting daily air quality. It tells you how clean or polluted your air is, and what associated health effects might be a concern for you. The AQI focuses on health effects you may experience within a few hours or days after breathing polluted air. EPA calculates the AQI for five major air pollutants regulated by the Clean Air Act: ground-level ozone, particle pollution (also known as particulate matter), carbon monoxide, sulfur dioxide, and nitrogen dioxide. For each of these pollutants, EPA has established national air quality standards to protect public health. Ground-level ozone and airborne particles (often referred to as "particulate matter") are the two pollutants that pose the greatest threat to human health in this country.A number of factors influence ozone formation, including emissions from cars, trucks, buses, power plants, and industries, along with weather conditions. Weather is especially favorable for ozone formation when it’s hot, dry and sunny, and winds are calm and light. Federal and state regulations, including regulations for power plants, vehicles and fuels, are helping reduce ozone pollution nationwide.Fine particle pollution (or "particulate matter") can be emitted directly from cars, trucks, buses, power plants and industries, along with wildfires and woodstoves. But it also forms from chemical reactions of other pollutants in the air. Particle pollution can be high at different times of year, depending on where you live. In some areas, for example, colder winters can lead to increased particle pollution emissions from woodstove use, and stagnant weather conditions with calm and light winds can trap PM2.5 pollution near emission sources. Federal and state rules are helping reduce fine particle pollution, including clean diesel rules for vehicles and fuels, and rules to reduce pollution from power plants, industries, locomotives, and marine vessels, among others.How Does the AQI Work?Think of the AQI as a yardstick that runs from 0 to 500. The higher the AQI value, the greater the level of air pollution and the greater the health concern. For example, an AQI value of 50 represents good air quality with little potential to affect public health, while an AQI value over 300 represents hazardous air quality.An AQI value of 100 generally corresponds to the national air quality standard for the pollutant, which is the level EPA has set to protect public health. AQI values below 100 are generally thought of as satisfactory. When AQI values are above 100, air quality is considered to be unhealthy-at first for certain sensitive groups of people, then for everyone as AQI values get higher.Understanding the AQIThe purpose of the AQI is to help you understand what local air quality means to your health. To make it easier to understand, the AQI is divided into six categories:Air Quality Index(AQI) ValuesLevels of Health ConcernColorsWhen the AQI is in this range:..air quality conditions are:...as symbolized by this color:0 to 50GoodGreen51 to 100ModerateYellow101 to 150Unhealthy for Sensitive GroupsOrange151 to 200UnhealthyRed201 to 300Very UnhealthyPurple301 to 500HazardousMaroonNote: Values above 500 are considered Beyond the AQI. Follow recommendations for the Hazardous category. Additional information on reducing exposure to extremely high levels of particle pollution is available here.Each category corresponds to a different level of health concern. The six levels of health concern and what they mean are:"Good" AQI is 0 to 50. Air quality is considered satisfactory, and air pollution poses little or no risk."Moderate" AQI is 51 to 100. Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people. For example, people who are unusually sensitive to ozone may experience respiratory symptoms."Unhealthy for Sensitive Groups" AQI is 101 to 150. Although general public is not likely to be affected at this AQI range, people with lung disease, older adults and children are at a greater risk from exposure to ozone, whereas persons with heart and lung disease, older adults and children are at greater risk from the presence of particles in the air."Unhealthy" AQI is 151 to 200. Everyone may begin to experience some adverse health effects, and members of the sensitive groups may experience more serious effects."Very Unhealthy" AQI is 201 to 300. This would trigger a health alert signifying that everyone may experience more serious health effects."Hazardous" AQI greater than 300. This would trigger a health warnings of emergency conditions. The entire population is more likely to be affected.AQI colorsEPA has assigned a specific color to each AQI category to make it easier for people to understand quickly whether air pollution is reaching unhealthy levels in their communities. For example, the color orange means that conditions are "unhealthy for sensitive groups," while red means that conditions may be "unhealthy for everyone," and so on.Air Quality Index Levels of Health ConcernNumericalValueMeaningGood0 to 50Air quality is considered satisfactory, and air pollution poses little or no risk.Moderate51 to 100Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.Unhealthy for Sensitive Groups101 to 150Members of sensitive groups may experience health effects. The general public is not likely to be affected.Unhealthy151 to 200Everyone may begin to experience health effects; members of sensitive groups may experience more serious health effects.Very Unhealthy201 to 300Health alert: everyone may experience more serious health effects.Hazardous301 to 500Health warnings of emergency conditions. The entire population is more likely to be affected.Note: Values above 500 are considered Beyond the AQI. Follow recommendations for the "Hazardous category." Additional information on reducing exposure to extremely high levels of particle pollution is available here.

US Air Quality Metrics Dataset (2000-2023)

Overview and Data Compilation

This dataset spans from the year 2000 to 2023, comprising around 665,414 observations across 21 columns. It provides an analysis of air quality in the United States, with an emphasis on pollutants like Nitrogen Dioxide (NO2), Sulphur Dioxide (SO2), Carbon Monoxide (CO), and Ozone (O3). The data has been continuously updated, and most recently extended to include 2023 data, enhancing its research value.

Data Sources and Acknowledgments

The foundation of this dataset lies in the data provided by the U.S. Environmental Protection Agency (EPA). Significant contributions have also been made by Kagglers BrendaSo and ANGELA KIM, enriching its scope and utility.

This dataset serves as a dynamic resource for researchers, policy-makers, and those interested in the trends and implications of air quality in the United States.

• Orignal Source: US EPA AQS Data

EPA Air Quality System annual AQI data for 995 counties, 501 metros, and 53 states covering 2020-2024.

The City of Detroit has installed seven Teledyne T640x air quality monitors at fixed locations across the city to measure real-time particulate matter (PM) in ambient air. The measurement and collection of public real-time and historical air pollution data provides additional information for the public, organizations, and local and state regulators to make informed air quality decisions, educate the public regarding the interaction of air quality, regulations and health, and provide necessary data to manage and regulate air quality in the region. This air quality monitoring project seeks to supplement existing monitoring efforts in Detroit from the State of Michigan Department of Environment, Great Lakes, and Energy (EGLE), Wayne County, and citizen and community group monitors, and aims to collectively provide coverage across every Detroit City Council district.This database presents the locations of the monitors, hourly averages for PM10 (PM less than 10 micrometers in aerodynamic diameter/particle size), PM2.5 (PM less than 2.5 micrometer particle size), PMcoarse (PM between particle size 2.5-10 micrometers), the air quality index (AQI) calculated for both PM10 and PM2.5, and representative meteorological data for each monitor (wind speed, direction, and temperature) from the closest Michigan Department of Environment, Great Lakes, and Energy (EGLE) meteorological station. The T640x option is an approved Federal Equivalent Method (FEM) for PM2.5, PM10 and PMcoarse, designating the method as acceptable for use in state or local air quality surveillance systems. The database will be updated daily with historical data available for download, while the live data dashboard showing current data is updated hourly.The AQI is EPA’s tool for categorizing and communicating air quality into levels of health concern, with specific information for which groups of people may be affected and preventative measures to reduce exposure.[1] Historical AQI data present an AQI for the 24-hour period prior- for example the AQI at the end of a given day will give a representative value for the air quality over the full course of the day. Real-time AQI reporting is calculated using EPA’s NowCast methodology, which uses an algorithm that relates hourly readings from air quality monitors to the AQI using a weighted average of the previous 12 hours.[2] For the historical data download, note that for past dates the AQI value should be used instead of the NowCast AQI, as noted it will give a representative value for the full day. Both real-time and downloaded data is preliminary and subject to change, and monthly QA/QC reports will be posted that will include any data corrections made for periods of calibration or maintenance. *Data Flag – Monitoring Station 1 (DPD 6th Precinct) used a replacement Teledyne T640 from 7/2/25 until 10/21/25. While the Teledyne T640 still measures PM2.5, PM10 and PMcoarse, only the PM2.5 measurments meet FEM requirements. A visualization of the Air Quality Monitor Readings is available from the open data Analytics Hub[1] U.S. EPA. Technical Assistance Document for the Reporting of Daily Air Quality- the Air Quality Index (AQI). EPA-454/B-24-002. May 2024. https://document.airnow.gov/technical-assistance-document-for-the-reporting-of-daily-air-quailty.pdf.[2] Id at 16.

This United States Environmental Protection Agency (US EPA) feature layer represents site data, updated hourly concentrations and Air Quality Index (AQI) values for the last 24 hours received from each monitoring site that reports to AirNow. NOTE: Time Animation is enabled by default on this layer.Map and forecast data are collected using federal reference or equivalent monitoring techniques or techniques approved by the state, local or tribal monitoring agencies. To maintain "real-time" maps, the data are displayed after the end of each hour. Although preliminary data quality assessments are performed, the data in AirNow are not fully verified and validated through the quality assurance procedures monitoring organizations used to officially submit and certify data on the EPA Air Quality System (AQS).This data sharing, and centralization creates a one-stop source for real-time and forecast air quality data. The benefits include quality control, national reporting consistency, access to automated mapping methods, and data distribution to the public and other data systems. The U.S. Environmental Protection Agency, National Oceanic and Atmospheric Administration, National Park Service, tribal, state, and local agencies developed the AirNow system to provide the public with easy access to national air quality information. State and local agencies report the Air Quality Index (AQI) for cities across the US and parts of Canada and Mexico. AirNow data are used only to report the AQI, not to formulate or support regulation, guidance or any other EPA decision or position.About the AQIThe Air Quality Index (AQI) is an index for reporting daily air quality. It tells you how clean or polluted your air is, and what associated health effects might be a concern for you. The AQI focuses on health effects you may experience within a few hours or days after breathing polluted air. EPA calculates the AQI for five major air pollutants regulated by the Clean Air Act: ground-level ozone, particle pollution (also known as particulate matter), carbon monoxide, sulfur dioxide, and nitrogen dioxide. For each of these pollutants, EPA has established national air quality standards to protect public health. Ground-level ozone and airborne particles (often referred to as "particulate matter") are the two pollutants that pose the greatest threat to human health in this country.A number of factors influence ozone formation, including emissions from cars, trucks, buses, power plants, and industries, along with weather conditions. Weather is especially favorable for ozone formation when it’s hot, dry and sunny, and winds are calm and light. Federal and state regulations, including regulations for power plants, vehicles and fuels, are helping reduce ozone pollution nationwide.Fine particle pollution (or "particulate matter") can be emitted directly from cars, trucks, buses, power plants and industries, along with wildfires and woodstoves. But it also forms from chemical reactions of other pollutants in the air. Particle pollution can be high at different times of year, depending on where you live. In some areas, for example, colder winters can lead to increased particle pollution emissions from woodstove use, and stagnant weather conditions with calm and light winds can trap PM2.5 pollution near emission sources. Federal and state rules are helping reduce fine particle pollution, including clean diesel rules for vehicles and fuels, and rules to reduce pollution from power plants, industries, locomotives, and marine vessels, among others.How Does the AQI Work?Think of the AQI as a yardstick that runs from 0 to 500. The higher the AQI value, the greater the level of air pollution and the greater the health concern. For example, an AQI value of 50 represents good air quality with little potential to affect public health, while an AQI value over 300 represents hazardous air quality.An AQI value of 100 generally corresponds to the national air quality standard for the pollutant, which is the level EPA has set to protect public health. AQI values below 100 are generally thought of as satisfactory. When AQI values are above 100, air quality is considered to be unhealthy-at first for certain sensitive groups of people, then for everyone as AQI values get higher.Understanding the AQIThe purpose of the AQI is to help you understand what local air quality means to your health. To make it easier to understand, the AQI is divided into six categories:Air Quality Index(AQI) ValuesLevels of Health ConcernColorsWhen the AQI is in this range:..air quality conditions are:...as symbolized by this color:0 to 50GoodGreen51 to 100ModerateYellow101 to 150Unhealthy for Sensitive GroupsOrange151 to 200UnhealthyRed201 to 300Very UnhealthyPurple301 to 500HazardousMaroonNote: Values above 500 are considered Beyond the AQI. Follow recommendations for the Hazardous category. Additional information on reducing exposure to extremely high levels of particle pollution is available here.Each category corresponds to a different level of health concern. The six levels of health concern and what they mean are:"Good" AQI is 0 to 50. Air quality is considered satisfactory, and air pollution poses little or no risk."Moderate" AQI is 51 to 100. Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people. For example, people who are unusually sensitive to ozone may experience respiratory symptoms."Unhealthy for Sensitive Groups" AQI is 101 to 150. Although general public is not likely to be affected at this AQI range, people with lung disease, older adults and children are at a greater risk from exposure to ozone, whereas persons with heart and lung disease, older adults and children are at greater risk from the presence of particles in the air."Unhealthy" AQI is 151 to 200. Everyone may begin to experience some adverse health effects, and members of the sensitive groups may experience more serious effects."Very Unhealthy" AQI is 201 to 300. This would trigger a health alert signifying that everyone may experience more serious health effects."Hazardous" AQI greater than 300. This would trigger a health warnings of emergency conditions. The entire population is more likely to be affected.AQI colorsEPA has assigned a specific color to each AQI category to make it easier for people to understand quickly whether air pollution is reaching unhealthy levels in their communities. For example, the color orange means that conditions are "unhealthy for sensitive groups," while red means that conditions may be "unhealthy for everyone," and so on.Air Quality Index Levels of Health ConcernNumericalValueMeaningGood0 to 50Air quality is considered satisfactory, and air pollution poses little or no risk.Moderate51 to 100Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.Unhealthy for Sensitive Groups101 to 150Members of sensitive groups may experience health effects. The general public is not likely to be affected.Unhealthy151 to 200Everyone may begin to experience health effects; members of sensitive groups may experience more serious health effects.Very Unhealthy201 to 300Health alert: everyone may experience more serious health effects.Hazardous301 to 500Health warnings of emergency conditions. The entire population is more likely to be affected.Note: Values above 500 are considered Beyond the AQI. Follow recommendations for the "Hazardous category." Additional information on reducing exposure to extremely high levels of particle pollution is available here.

AQI: Alabama: Mobile data was reported at 30.000 Index in 05 Mar 2026. This records a decrease from the previous number of 38.000 Index for 04 Mar 2026. AQI: Alabama: Mobile data is updated daily, averaging 40.000 Index from Jan 1980 (Median) to 05 Mar 2026, with 16024 observations. The data reached an all-time high of 139.000 Index in 24 Jan 2017 and a record low of 0.000 Index in 31 Dec 2023. AQI: Alabama: Mobile data remains active status in CEIC and is reported by United States Environmental Protection Agency. The data is categorized under Global Database’s United States – Table US.ESG.E: Air Quality Index and Air Pollutants. [COVID-19-IMPACT]

The Air Quality Index (AQI) for each monitoring station is provided hourly. The original data version is announced on the Air Quality Monitoring Network website https://airtw.moenv.gov.tw

This image visually represents air quality data, including key pollutants such as CO, NOx, NO₂, O₃, SO₂, PM2.5, and PM10. It features an Air Quality Index (AQI) gauge, indicating the pollution level from good (green) to hazardous (red). The background showcases an urban cityscape, highlighting the impact of air pollution. Additional graphical elements like bar charts, clouds, and weather indicators (temperature, humidity, and wind speed) make this an informative and data-driven visualization for environmental monitoring and analysis.

Ideal for use as a header image in reports, dashboards, or presentations related to air quality prediction, pollution control, and environmental research. 🚀🌍💨

This dataset provides a summary of annual air pollution statistics from 1995 to the current available year for six air pollutants:

• Carbon Monoxide
• Oxides of Nitrogen (NO, NO2, NOx)
• Ozone
• Fine Particulate Matter (PM2.5)
• Sulphur Dioxide
• Total Reduced Sulphur

The annual statistics include percentiles, mean, maximums and also indicate the number of times an air monitoring station exceeded an Ontario annual ambient air quality criteria, where applicable. This information is also available in the annual Air Quality in Ontario Reports. The hourly air pollutant concentration data is posted in near real time on the Air Quality Ontario website: http://www.airqualityontario.com/

Dataset contains information on New York City air quality surveillance data.

Air pollution is one of the most important environmental threats to urban populations and while all people are exposed, pollutant emissions, levels of exposure, and population vulnerability vary across neighborhoods. Exposures to common air pollutants have been linked to respiratory and cardiovascular diseases, cancers, and premature deaths. These indicators provide a perspective across time and NYC geographies to better characterize air quality and health in NYC. Data can also be explored online at the Environment and Health Data Portal: http://nyc.gov/health/environmentdata.

Real-time air quality data can be found on the Environmental & Health Data Portal linked here: Real-Time Air Quality in NYC

The Country Trends in Major Air Pollutants data set is a framework of public-health-focused air quality indicators that quantifies over 200 countries' trends in exposure to Particulate Matter (PM2.5), Ozone (O3), Nitrogen Oxides (NOx), Sulfur Dioxide (SO2), Carbon Monoxide (CO), and Volatile Organic Compounds (VOCs). Pollutant concentration data are derived from the European Centre for Medium-Range Weather Forecasts (ECMWF) Atmospheric Composition Reanalysis 4 (EAC4) data sets, freely available from the Copernicus Atmospheric Monitoring Services' Atmospheric Data Store (https://ads.atmosphere.copernicus.eu). CIESIN's Gridded Population of the World, Version 4 (GPWv4): Population Count Adjusted to Match 2015 Revision of UN WPP Country Totals, Revision 11 was used in the population weighting algorithm.

This dataset is provided by the UK Department for Environment, Food & Rural Affairs (DEFRA) and contains air quality monitoring data collected from the CLL2 monitoring site. The data is published in flat file format and represents systematically recorded environmental measurements over time.

The dataset consists of time-series tabular data, where each record corresponds to a specific date and time at which air pollutant concentrations were measured. It includes quantitative measurements of key air quality indicators such as nitrogen dioxide (NO₂), particulate matter (PM₁₀ and PM₂.₅), ozone (O₃), and other regulated pollutants, depending on availability at the monitoring station.

Measurements are reported with standardized units and follow official UK air quality monitoring protocols. The data is primarily recorded at hourly resolution, allowing for detailed temporal analysis of pollution patterns, trends, and short-term fluctuations. Missing or invalid measurements may be present and are typically encoded using predefined flags or null values, reflecting routine instrument calibration, maintenance, or data quality checks.

This dataset is suitable for:

• air quality trend and seasonal analysis,
• environmental and public health studies,
• time-series modeling and forecasting,
• correlation analysis with meteorological or urban activity data.

Overall, the dataset provides a reliable and structured source of real-world environmental measurements that can be directly used in statistical analysis, visualization, and machine learning workflows.

AQI: Arizona: Phoenix-Mesa-Scottsdale: SO2 data was reported at 1.000 Index in 30 Sep 2023. This records a decrease from the previous number of 3.000 Index for 29 Sep 2023. AQI: Arizona: Phoenix-Mesa-Scottsdale: SO2 data is updated daily, averaging 3.000 Index from Jan 1980 (Median) to 30 Sep 2023, with 15582 observations. The data reached an all-time high of 94.000 Index in 14 Nov 2017 and a record low of 0.000 Index in 17 Jul 2023. AQI: Arizona: Phoenix-Mesa-Scottsdale: SO2 data remains active status in CEIC and is reported by United States Environmental Protection Agency. The data is categorized under Global Database’s United States – Table US.ESG.E001: Air Quality Index and Air Pollutants. [COVID-19-IMPACT]

This dataset encompasses air quality data collected from various urban monitoring stations over a period from 2007 to 2023. It captures levels of multiple pollutants including nitrogen dioxide, sulfur dioxide, ozone, particulate matter, ammonia, and carbon dioxide. The data provides valuable insights into environmental trends and urban sustainability. It enables the analysis of how air pollution levels fluctuate across different cities and time periods. The dataset is useful for studying the impact of pollution on public health and urban ecosystems. It serves as a comprehensive resource for understanding air quality and its implications for smart cities.

AQI: Connecticut: Hartford-West Hartford-East Hartford: CO data was reported at 3.000 Index in 23 Sep 2025. This records a decrease from the previous number of 6.000 Index for 22 Sep 2025. AQI: Connecticut: Hartford-West Hartford-East Hartford: CO data is updated daily, averaging 7.000 Index from Jan 1980 (Median) to 23 Sep 2025, with 15988 observations. The data reached an all-time high of 22.000 Index in 09 Nov 2016 and a record low of 1.000 Index in 23 May 2025. AQI: Connecticut: Hartford-West Hartford-East Hartford: CO data remains active status in CEIC and is reported by United States Environmental Protection Agency. The data is categorized under Global Database’s United States – Table US.ESG.E: Air Quality Index and Air Pollutants. [COVID-19-IMPACT]

This dataset compiles air quality measurements from various states across India, focusing on six key pollutants and their corresponding Air Quality Index (AQI) values calculated using Indian national standards.

Columns included:

• PM2.5 (µg/m³)
• PM10 (µg/m³)
• NO₂ (µg/m³)
• SO₂ (µg/m³)
• CO (mg/m³)
• O₃ (µg/m³)
• AQI (Indian Standard) ###### Key Features:
• All pollutant concentrations are standardized to micrograms per cubic meter (µg/m³), except CO, which is in milligrams per cubic meter (mg/m³).
• AQI values are computed using the Indian National Air Quality Standards (NAAQS) methodology.
• Data spans multiple Indian states, offering regional diversity and insight into urban and semi-urban pollution levels.

1) AQI and Pollutants

The Air Quality Index (AQI) is a standardized indicator used to measure air quality in relation to various pollutants. The AQI levels range from 0 to 500, with higher values indicating worse air quality and potential health risks. The pollutants tracked in this dataset include:

• PM2.5: Fine particulate matter with a diameter of less than 2.5 micrometers. These particles are capable of penetrating deep into the lungs and bloodstream, causing respiratory and cardiovascular issues.
• PM10: Particulate matter with a diameter less than 10 micrometers. These particles can cause respiratory irritation but are not as invasive as PM2.5.
• SO2: Sulfur Dioxide is a toxic gas produced primarily by fossil fuel combustion, which can lead to respiratory problems.
• NOx: A group of nitrogen oxides (including NO2 and NO) generated by combustion engines, contributing to smog and acid rain.
• CO: Carbon Monoxide is a colorless, odorless gas that can be harmful when inhaled in large amounts. It primarily originates from vehicle emissions and other combustion sources.
• O3: Ozone is a gas that forms in the atmosphere and is harmful at ground level. It’s a major component of smog and can cause respiratory issues.

2) Metadata

3) Data Value

This dataset analyzes air quality trends and relationships between various pollutants. Here are a few potential uses:

• Regression Analysis: You can use regression techniques to predict AQI based on levels of specific pollutants like PM2.5, CO, and SO2. By treating AQI as the target variable(Remove Status column), you can build models to predict how pollutant concentrations impact air quality.

• Time Series Forecasting: Using the date field, you can perform time series analysis to forecast future air quality levels based on historical pollutant concentrations, wind speed, and direction.

• Spatial Analysis: Given the latitude and longitude columns (Country), you can visualize spatial trends in air quality, possibly identifying regions with consistently poor or good air quality.

Feel free to leave comments on the discussion. I'd appreciate your upvote if you find my dataset useful! 😀